Actually, I think when I said "always distracting" I was thinking about myself. I'm pretty much in front of a computer during my entire waking hours, so always involved with text. I agree that it doesn't have to be distracting for other kinds of activities like manual work.

With the ADHD study, I wonder if that might work by the music actually distracting them, but not by as much as other things would distract them without the music. Of course even if this is the case, the study would still show that it is helpful for them.